Solid analysis

Solid analyses (Moisture free) ISGS Std. Coal 1 (moisture free) % Total Sulfur 4.23b 2.69 2.64 2.94 1.95... 

Quantitative Analysis. When the relative accuracy of thin-film EDS analyses in an AEM is compared with other analytical techniques, it is instructive to consider the precision in terms of both spatial resolution and elemental abundance. Few techniques offer the same combination of high spatial resolution and elemental analysis for solids - analyses with 5% relative accuracy from areas <20nm in diameter. 

All of the tests were performed using a sample size of 50 mL. Determine the concentration of total solids, total volatile solids, suspended solids, volatile suspended solids, total dissolved solids, and total volatile dissolved solids. The samples used in the solids analyses were all evaporated, dried, or ignited to constant weight. 

Laser Ablation [7]. The modern method for quantitative solid analyses is carried out using a laser ablation technique (Figure 2.16). The laser, usually in the form of Nd YAG (Neodymium - Doped Yttrium Aluminium Garnet), is focused on to the surface of a sample which, by continuous pulsing, leads to vaporisation at that point and the vapour is transported directly to the plasma with argon for detection and quantification. Detection limits are... 

Fig. 7.13 The Rheometrics Solids Analyser RSA III. (a) A schematic diagram of the control system, (b) The oven doors are shown open with the oven drawn aside and a sample is shown ready for a bending test. (Courtesy of Rheometric Scientific GmbH.)...

Feed rate is most often the first parameter to be investigated. The capacity of the decanter is of fundamental interest to the user. The pond level and bowl speed will have been fixed during the preliminary testing. If flocculanl is to be used, then a safe dosing level will have been determined and used during the preliminary tests, after bench evaluation of likely polymers to be used. The safe dosing level will be such as to permit a wide range of feed rates and conveyor differentials, without any appreciable deterioration in centrate quality. A series of tests at. say. five different feed rates will be conducted and samples of feed, centrate and cake will be taken for solids analyses. 

If the secondary ion component is indeed negligible, the measured SNMS ion currents will depend only on the ionizing mode, on the atomic properties of the sputtered atoms, and on the composition of the sputtered sample. Matrix characteristics will have no effect on the relative ion currents. SNMS analysis also provides essentially complete coverage, with almost all elements measured with equal facility. All elements in a chemically complex sample or thin-film structure will be measured, with no incompleteness due to insensitivity to an important constituent element. Properly implemented SNMS promises to be a near-universal analytical method for solids analysis. 

The reaction is quenched by the addition of 1.28 g (2.94 mmol) of molybdenum pentoxidc/pyridinc/UMPA, and the yellow slurry is stirred initially at OX (30 min), then for 45 min at 25 X. The mixture is added to 1 N sodium hydroxide and extracted with diethyl ether. The ethereal solution is washed with brine, dried over Na,S04 and concentrated in vacuo to give 0.705 g (100%) of an oily, light-yellow solid. Analysis of the crude aldol adduct by 1 C NMR and analytical HPLO (Waters, Radial Pak, 8 mm x 10 cm, silica gel, ethyl acetate/hexane, 15 85) indicates only one. un-diastereomer (2X3S ) accompanied by approximately 10% of the two ethyl acetate/hexane affords fine white needles yield 0.359 g (57%) mp 155.5 156.5X (a]u -92.5 (c = 0.0294, CHCfi). 

FAB-MS is a renewed old technique, first described in 1966 as molecular beam for solid analysis (MBSA) [73], and later (1981) further extended with a liquid matrix [72,74], The FAB experiment is closely related to... 

Table 8.22 shows some rubber analyses by FAAS after dry ashing. The concentration of Rh in polymers was measured by FAAS [128], The accuracy of 10-20% was in agreement with a dissolution procedure the precision obtained for direct solid analysis was between 10 and 20 %. Due to the relatively high analyte content of lead in paint, the determination is mostly performed by FAAS. Typical digestion procedures include dry ashing, wet and microwave digestion. 

Applications Specific applications of the direct spectrometric analysis methods of solid samples of Table 8.36 are given under the specific headings. One investigation that is practically only possible by direct solids analysis is checking the homogeneity of polymers [136,137] this is of significance for reference materials and for quality control. A method for the assessment of microhomogeneity should meet various requirements [223] ... 

For new analytical techniques to prosper, they must have demonstrated applications to real-world samples, with outstanding figures of merit relative to competing approaches. Table 10.24 opposes the prospects of conventional separation procedures and advanced in situ analyses by the currently most qualifying techniques. Lab-on-a-chip (LOC) devices are unlikely to be robust enough to cope with the moderately complex (i.e. dirty ) matrices that are real-life samples. Industrial chemists need to avoid a lot of work for every analyte and every matrix. Obstacles to solid analysis are relatively poor sensitivities, narrow linear dynamic ranges and unavailability of solid standards. The trend... 

During operation, samples of all flows were taken for suspended solids analysis. These tests were performed by a qualified local analytical laboratory. Procedures for this analysis were as outlined in standard methods.47 Glass fiber filter pads with a particle size retention of 1.2 pm were used. 

DGE a AC AMS APCI API AP-MALDI APPI ASAP BIRD c CAD CE CF CF-FAB Cl CID cw CZE Da DAPCI DART DC DE DESI DIOS DTIMS EC ECD El ELDI EM ESI ETD eV f FAB FAIMS FD FI FT FTICR two-dimensional gel electrophoresis atto, 10 18 alternating current accelerator mass spectrometry atmospheric pressure chemical ionization atmospheric pressure ionization atmospheric pressure matrix-assisted laser desorption/ionization atmospheric pressure photoionization atmospheric-pressure solids analysis probe blackbody infrared radiative dissociation centi, 10-2 collision-activated dissociation capillary electrophoresis continuous flow continuous flow fast atom bombardment chemical ionization collision-induced dissociation continuous wave capillary zone electrophoresis dalton desorption atmospheric pressure chemical ionization direct analysis in real time direct current delayed extraction desorption electrospray ionization desorption/ionization on silicon drift tube ion mobility spectrometry electrochromatography electron capture dissociation electron ionization electrospray-assisted laser desorption/ionization electron multiplier electrospray ionization electron transfer dissociation electron volt femto, 1CT15 fast atom bombardment field asymmetric waveform ion mobility spectrometry field desorption field ionization Fourier transform Fourier transform ion cyclotron resonance... 

There are some variants that have emerged in the wake of DESI. By replacing the electrospray emitter by a metal needle and allowing solvent vapor into the coaxial gas flow desorption APCI (DAPCI) can be performed [106], Other versions are atmospheric-pressure solids analysis probe (ASAP) where a heated gas jet desorbs the analyte, which is subsequently ionized by a corona discharge [107], and electrospray-assisted laser desorption/ionization (ELDI) where a laser ablates the analyte and charged droplets from an electrospray postionizes the desorbed neutrals [108],... 

The solids analysis described above can be taken to yet another level by correlating the color measurement to chemical properties. An excellent model system is vanadium pyrophosphate (VPO), which is a well-known catalyst for butane oxidation to maleic anhydride. During the synthesis of the catalyst precursor, solid V2O5 particles are dispersed in a mixture of benzyl alcohol and i-butanol. In this slurry phase, the vanadium is partly reduced. Addition of phosphoric acid leads to a further reduction and the formation of the VPO structure. With a diffuse reflectance (DR) UV-vis probe by Fiberguide Ind., the surface of the suspended solid particles could be monitored during this slurry reaction. Four points can be noted from Figure 4.4 ... 

He gave the project to an assistant, who tried all sorts of reaction conditions — to no avail. Then one weekend he left one of his experiments sitting in a flask and discovered on Monday morning that it had turned into a rubbery solid. Analysis showed that residual hydrochloric acid had reacted with the vinylacetylene to make a synthetic rubber. Neoprene... 

Finally, direct solid analysis by optical and mass spectrometry will be presented in Section 1.5. This alternative is becoming more appealing nowadays and implemented in laboratories because of the many advantages brought about by eliminating the need to dissolve the sample. Techniques based on the use of atomiser/excitation/ionisation sources such as sparks, lasers and glow discharges will be briefly described in that section. 

A few representative and widely used techniques based on optical and mass spectrometry for direct solid analysis have been selected for further explanation here. As was stated in the introductory section (see Section 1.1), analytical... 

Very often, techniques for direct solid analysis are classified into two groups according to whether they provide bulk information (of interest for homogeneous samples) or analytical information with lateral and/or depth resolution. 

Figure 1.15 Comparison of the lateral and depth resolution allowed by different optical and mass spectrometric techniques used for direct solid analysis (A, IG, incident and emitted ions, respectively cT, electrons ho, photons). XPS and AES are included in the graph for comparison.

Three direct solid analysis mass spectrometric techniques allowing for lateral and/or depth resolution have been selected in this section laser ablation (LA) coupled to ICP-MS, secondary ion mass spectrometry (SIMS) and GD-MS. 

Dimethoxycopper(II) is a moisture-sensitive blue compound that is insoluble in common organic solvents. It can be recrystallized from MeOH/NH3 to give a microcrystalline solid. Analysis of copper by iodometric titration provides a quick routine purity determination for dimethoxycopper(II).8 The complete removal of residual chloride from dimethoxycopper(II) is not easily achieved the most likely impurity is CuCl(OMe), which is a green compound.5 Dimethoxycopper(II) must be washed thoroughly as described above to minimize contamination by CuCl(OMe), and is obtained in >98% purity by this procedure (on the basis of the C, H, Cl, Cu, and Li analyses). IR (KBr, cm 1) 2917(vs), 2885(vs), 2806(vs), 1436(w), 1150(w), 1052(vs), 528(vs), 438(s). 

No magnesium sulfate was added to the system for run MG-3. The objective of this run was to evaluate the system performance with decreasing Mg2+ concentration. The mass balance indicated that the total Mg2 concentration should drift down to below 500 ppm. During the run, the total Mg2+ concentration decreased from 1000 ppm to about 625 ppm toward its end. A leak was discovered at the scrubber bleed/quench recirculation pump inlet which introduced air into the process stream and therefore caused high oxidation. The high oxidation, as confirmed by solids analysis results in Table 3, was reflected by increases of the sulfate-to-sulfite ratio to above 2.5. After the air leak problem was corrected, the sulfate-to-sulfite ratio decreased, but the test average was 2.4. 

The authors wish to acknowledge Sharon Kaffen for her synthesis of the PMMA latexes, Farrokh Malihi for QELS and turbidity measurements, C. M. Neag for percent solids analysis by thermogravimetry and C. B. Rakowski of SCM Pigments for the TEM measurements ... 

Through the combined use of catalytic probe reactions, Mossbauer, EXAFS, XPS, XRD, it has been demonstrated that the anticipated particle structures for the half-SMAD and full SMAD procedures are close to reality.(40-42) Thus, 119Sn Mossbauer, a bulk solid analysis technique, revealed the relative amounts of Sn, Pt-Sn alloy, SnO, and Sn02 present in the catalysts. It was possible to differentiate Sn° from Pt-Sn alloy through supporting evidence of XPS and selective oxidation, since it was found that ultra-fine Sn° particles were much more susceptible to oxidation than Pt-Sn alloy particles. Also, since the full SMAD Pt°-Sn°/Al203 catalysts behaved much differently than Pt°/Al203, it is clear that the SMAD catalysts are not made up of separate Pt° and Sn particles. 

This chapter deals exclusively with the methods that have been developed for the direct solids analysis of nonconductive samples by glow discharge mass spectrometry. The basic approaches to operation and sample preparation for the three primary methodologies of compaction, secondary cathode, and radio frequency powering are described. Examples of source performance and practical applications of each are taken from the analytical literature. Whereas this chapter de-... 

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